Page 74 - Cyber Warnings August 2017

But verifying trust consistently is difficult if encryption is not implemented consistently across
environments from boot—a practice that allows enterprises to avoid mistakes and malicious
activity.

2. Maintain Absolute Key Control

For full control over assets, enterprises need absolute control over keys. This control allows enterprises
to ensure that sensitive assets are encrypted and remain so, and to determine how data is used and by
what entities.

Unfortunately, even if provider-offered encryption is described as “customer controlled,” keys
may or may not be permitted to reside on the enterprise’s premises. Storing keys on-premises in
a hardware security module (HSM) or in a secure, customer-owned environment is the only way
to confirm that third-party access has been prevented and that keys can be changed if issues
arise. Any enterprise subject to compliance concerns should be particularly aware of this
practice, as key control plays a big role in many major regulations, including PCI DSS and
HIPAA.

3. Ensure Tight Key Access and Authentication

Tight management of key access and authentication of access is critical to eliminating misuse of
keys. The single-key nature of CSP-offered encryption such as AWS’s Key Management
System means that any user with access to the Customer Master Key can decrypt resources.

Access to keys should be authenticated and logged for maximum visibility. Without control over
key access, it is difficult for IT to ensure that it can be agilely responsive to any possible
breaches or back doors. To further eliminate these risks, encryption should be managed with a
consistent key management framework across environments.

4. Enforce Regular Key Rotation

Key rotation (both temporally and spatially) is essential for effective encryption. The amount of
time any given key is used should be limited, so limited exposure occurs in the event of
compromise. Likewise, the amount of data that is protected by any given key should also be
limited, so that any key permits access to only a small amount of sensitive data.

Automating rotation of keys and the amount of data that the enterprise encrypts with any given
key cuts down on operational overhead. Further, having a single encryption scheme across
environments helps ensure consistent and regular key rotation, simplifying the process
exponentially.

5. Evaluate Solutions for Agility

Enterprises need to ensure that crypto agility is at the heart of whatever encryption solution they
adopt. If a back door is discovered, a popular encryption algorithm is compromised, or a major
breach occurs, IT security teams must be able to nimbly respond and protect the security of
enterprise assets. The ability to revoke keys and set up new crypto in place of the original
algorithm is essential, but many solutions on the market don’t make that process simple.
Without crypto agility as a guiding principle for the encryption solution in place, IT cannot
guarantee an agile response.

74 Cyber Warnings E-Magazine – August 2017 Edition
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